In general, automatic white balancing refers to an imaging technique of reproducing a white object as a white image according to a light source illuminating the white object, such as sunlight, a fluorescent lamp, an incandescent room lamp, or the like.
Since human beings are adapted to colors, they can properly distinguish color differences of an object depending on the change in the lighting and location. However, since cameras are not adapted to colors, color differences of an object are reproduced according to the lighting and location. Accordingly, in order to control a phenomenon that changes colors of an object according to light sources of a camera, an automatic white balance technique is employed.
In an automatic white balance technique, areas of an input image are searched and gains of various channels are adjusted using an average of red, green and blue (RGB) values or chrominance signals (R-Y (luma)), (B-Y) of image data corresponding to the searched gray areas.